REQUEST: activate previous / next button for selected files

So the Extended Tags icon has two two buttons: << and >>

They allow to circle through files, right? But what files? Every files? Yes- and no. Because those buttons are only active when only one file is selected, thus showing the Extended Tags window from where start the navigation. But if you select even as little as two files, the those button will be shown inactive [greyed out]

Ans so if the user wants to quickly compare every tag fields of two files it is simply impossible. Instead of that the user has to:

1] Check with Extended Tags what fields has file 1 and remember them somehow

2] Check with Extended Tags what fields has file 2 and remember them somehow

3] Check and if necessary turn on Columns for every field used by file 1

4] Check and if necessary turn on Columns for every field used by file 2

5] Create new columns for fields that were missing in the Columns management window

or alternatively the user has to perform steps 3-5 in the Tag Panel. And that is just extremely not user friendly and in no way can be called quick. But if the Extended Tags window would no loose one of its functions when selection of multiple files ours then all of those 5 steps would be unnecessary

Instead of the 5 steps, you can either use a filter so that only those files that you want to treat are visible in the list.
Esp. if you want to compare fields I assume that they are fairly similar so that a common criterium should easily be found.
Also, if you have 2 files and the respective field in the extended tags dialogue does not show the data but , they are different so no more comparing necessary.

Or you drag&drop just these files from the Windows explorer.

That's a neat workaround

But if those are completely different files /criteria, then it stops being neat

So first take notice of files to be compared, then open each folder that has them, then... copy them to another folder so that they can be selected at once at dropped in Mp3tag? Or just move them, load them, compare them and move them back?

This workaround is bonkers; this would on work if the files were in the same folder from the get go

Did you know that you can d&d further files into the already filled file list if you press the Ctrl key while dragging&dropping? This adds the dragged&dropped files to the already existing list.
No moving about in the file system required.
And now you must help me: I simply cannot think of data that I want to compare but that does not have some criteria in common - this is what I understood from

Could you give a real example instead of just theoretical musing?

But how exactly do you intend to

at once, if they happen to be from different folders?

I would like to use the >> and << buttons regardless of the position of files on the list - so that I could select whatever files from whatever source, no matter how far apart from each other they would be on the list in the main window. If I select files then they should be added to some temporary list, through which Extended Tags icon cold cycle - because now it can cycle only through the whole list. And yes: I can shorten the list of 20 000 files with filtering expression - but why I cannot create such sub-list by the means of manual selection? How simple would that be? You just select whatever file you see, press ET icon and there you go- cycling through them

You might be looking for errors / misspellings; you might want to reorganize your system; you might be checking or tempering with mapping; thus needing to compare something / anything / everything

Like when you are merging files from two systems / groups? One of which may have stored year of publication of the album as YEAR and the other as ORIGYEAR; on top of which some may have been written with roman numerals and / or some of which may be completely empty or have some other info in them like a second year written in brackets which would-mean-you-do-not-know-what-and-you-would-fist-have-to-figure-it-out? Are you gonna say now that it still would be both easier and quicker to write a filtering expression that would take all of that into consideration - especially when you do not know that such brackets or roman numerals were used in the first place?